A:用100mL量筒量取95.63mL水
B:点燃氢气时,火焰呈淡蓝色,烧杯内壁有水珠出现
C:细铁丝在氧气中点燃时,剧烈燃烧,火星四射,生成黑色固体
D:硫在氧气中燃烧,会发出明亮的蓝紫色火焰,产生有刺激性气味的气体
—No. You______. There will be plenty of time.
—Oh, yes. “water and air is” should be “water and air are”.
秦汉时期的阶段特征为( )